• Toxicity of Dioxin
• Efforts to Combat Dioxin Pollution

The term "dioxin" refers to a group of persistent, organic pollutants that are among the most toxic chemicals known.

Dioxins are produced by incineration, the manufacture of chlorinated chemicals, particularly PVC, and in other processes using chlorine, such as paper bleaching. In the 1990s, the USEPA found that some 40% of the US's dioxin emissions to air came from medical waste incineration. One of the most important factors in this was the large proportion of PVC in medical waste. The chlorine that PVC contains is a vital ingredient for dioxin formation.

Toxicity of Dioxin

Because there are literally hundreds of dioxins, most laboratory research is done on the most toxic dioxin, 2,3,7,8-TCDD. This is classified as a known human carcinogen by both the International Agency for Research on Cancer (IARC) and the US Department of Health. It also affects the immune system, the reproductive system, the developing young, the hormone system, and causes other health problems including diabetes.

Dioxins can persist in the environment for thousands of years and can be transported around the globe via atmospheric or waterborne transport. They dissolve in fat and because they are eliminated from the body only very slowly, they accumulate in the food chain. As a result, top predators, including humans, can have very high concentrations. They are also passed on from mother to child, both before birth, and via breastfeeding. Breastfeeding is still by far the best way for a mother to nourish her child, so the best way to reduce exposure is to reduce the concentration of dioxin in the environment.

Efforts to Combat Dioxin Pollution

To combat dioxin pollution, over 150 nations have agreed to the terms of the Stockholm Convention on Persistent Organic Pollutants (the POPs Convention). Parties to the Convention are required to reduce or eliminate the release of persistent organic pollutants to the environment. Action to date includes global bans on several of the most toxic and persistent chlorinated pesticides, but since dioxins are not intentionally produced, they cannot be banned. Instead, the Convention mandates Best Available Technologies and Best Environmental Practices and to control dioxins and other unintentionally produced POPs.

This includes very stringent controls on dioxin emissions from incinerators. None of the small-scale incinerators common in low-income countries are able to meet these criteria. Although all incinerators produce dioxins, the problem is worse when PVC is burned. As a result, the Indian government prohibits the burning of PVC medical waste and the World Health Organisation (WHO) recommends avoiding PVC to reduce the problem. Ultimately, the only way to completely eliminate the problem of dioxin emissions from medical waste incineration is to switch to non-burn technologies.

HCWH is a principal cooperating agency in an 8-country project designed to facilitate the implementation of the Stockholm Convention. Funded by the Global Environment Facility (GEF) and managed by the United Nations Development Programme (UNDP), the project will reduce environmental releases of mercury and dioxins from healthcare facilities.

See more information on environmentally preferable medical waste treatment, PVC in healthcare, or visit our downloadable documents library.